Question: Which heterocyclic compound of drug used for treatment of mental disorder?
SPARQL (Wikidata):  select distinct ?obj where { wd:Q12135 wdt:P2176 ?obj . ?obj wdt:P31 wd:Q193430 } 
Answer: olanzapine, clozapine, haloperidol, quetiapine, aripiprazole, risperidone